Digital platforms have expanded the capacity of citizens to expose perceived wrongdoing, mobilise public attention and demand accountability. At the same time, the same visibility can produce forms of informal social control in which public judgement becomes reputational punishment. This article examines the boundary between collective accountability and collective punishment in digitally mediated public life in India. Drawing on qualitative interpretive analysis of scholarly literature and documented cases, it examines the June 2026 death by suicide of Samuel Garvyn De Braganca in Goa following the circulation of a video concerning alleged littering, and the 2026 online-harassment allegations made by Mumbai protester Rhiya Ahir. Rather than treating digital vigilantism as inherently harmful, the article examines the conditions under which citizen-led exposure moves from addressing an alleged act to sanctioning the person associated with it. Becker’s labelling theory and Goffman’s concept of stigma are considered alongside Papacharissi’s concept of affective publics and scholarship on digital vigilantism. The article proposes a trajectory from act to label, identity, reputation and potentially social exclusion. It argues that the boundary between accountability and punishment becomes blurred when rapid visibility, decontextualisation, emotional amplification and disproportionate reputational sanctions converge. Digital vigilantism is therefore approached as a contested form of informal social control whose consequences depend on how information is framed, circulated and acted upon by networked publics.